Suction roll seal assembly



Dec. 11, 1951 L. HORNBOSTEL 2,578,551

SUCTION ROLL SEAL ASSEMBLY Filed March 5, 1948 IYVEHTQP Patented Dec. 11, 1951 SUCTION ROLL SEAL ASSEMBLY Lloyd Hornhostel, Beloit, Wia., assignor to Beloit Iron Works, Beloit, Wis., a corporation of Wiscousin Application March 5, 1948, Serial No. 13,201

Claims.

This invention relates to improvements in seals for suction glands of suction rolls of the type used in the manufacture of paper. While the invention will be described with reference to paper making procedures it should be recognized that the invention may be used in suction rolls employed in other industries.

In suction rolls it is customary to provide a suction gland mounted stationarily inside of a perforated revolving cylinder. The two opposite margins of the suction gland are usually provided with adJustable seals of some type which have sliding pressure contact with the inner surface of the perforated cylinder wall. When the sealing strip material is of a soft resilient nature a metal carrier is frequently attached to the strip to prevent its deformation, but these carriers are themselves often a source of trouble.

In the present invention, the sealing strip itself may be formed from various materials but preferably a composition of the nature of a graphite impregnated phenolic resin is employed. This material is still enough not to require a metal jacket. A mounting block for the sealing strip is mounted at a desired point on the suction gland and the sealing strip is pressed into engagement with the inner surface of 'thesuction roll by means of a tube maintained under air pressure, while water maintained under pressure is supplied to the interior of the block so as to lubricate the sides of the sealing strip to make certain that the strip does not stick in the block.

One of the objects of the invention is to pro vide a sealing strip for a suction gland and a mounting therefor including an expansible tube for pressing the sealing strip against the suction roll and means for supplying water to lubricate the sides of the sealing strip.

Another objection of the invention is to provide a stationary mounting for a sealing strip in a suction gland provided with controllable expansion means for regulating the pressure of the seal against the suction roll and means for lubricating the sides of the sealing strip to assure its free movement within the mounting.

Other objects and advantages or the invention will be mentioned hereinafter or will become apparent from a perusal of the specifications.

In the drawing:

The single figure is a sectional view of a sealing strip and mounting mechanism therefor associated with the shell of a suction roll. in accord.- ance with this invention.

Referring further to the drawing, one wall ill of a typical suction gland is shown, provided with a flange H which extends toward the opposite wall (not shown) of the suction gland. It shouldbe understood that the wall II and flange H run the full length of the suction gland, parallel to the axis of the roll.

Mounted on top of the flange ii is a sealing strip holder provided with a flange l2 which 5 may be bolted to the flange it by a plurality of bolts such as it. The upper portion of the holder provides a pair of parallel side walls Hand it having a central vertical slot in which the sealing strip I6 is positioned for sliding movement. As

10 stated heretofore it is preferred that this strip be a composition of the nature of a graphite impregnated phenolic resin.

To assure maintaining the working face of the strip IS in contact with the inner surface of the i perforated cylinder ii I provide a tube-like bladder l8 seated in the bottom portion it of the vertical slot. This tube is preferably a heavy walled rubber tube and may be made of a synthetic type of rubber or natural rubber, and extends the entire length of the slot underneath the sealing strip. A pipe 20 connected to one end of the tube will supply air under regulatable pressure to the interior of this tube and by means of the air the pressure on the sealing strip may 25, thus be maintained and regulated.

As there would be a tendency for fibers and other foreign matter to enter the vertical slot along the sides of the sealing strip, I connect the water supply pipe 2i to the transverse pas- ;w sage 22 which communicates with the vertical passages 28 and 2t which are disposed at intervals throughout the length of the sealing strip holder. Also at intervals in the mounting block horizontal holes 25 and 26 are drilled to register with the vertical apertures 23 and 24 and to thus supply the water under pressure to the vertical sides of the sealing strip which extend down into registration with the horizontal apertures. The plates 2'! and 28 are then welded to the sides so of the mounting block to seal the laterally drilled holes.

- i Thus it is apparent that by supplying water under pressure through the tube 2! this water will follow along the sides of the sealing strip g5 it as far as the ho izontal packing strips 29 and it which are located in suitable grooves therefor near the upper margin of the mounting block. Some water, if the pressure be high, may even seep past the packing strips and lubricate t e sealing strip to the very top of the mounting block.

The tube It in addition to urging the sealing strip it against the cylinder wall also acts as a seal between the opposite sides'of the sealing strip because of its tight seal in the slot l9 and against the bottom edge of the sealing strip.

While the drawing shows but one sealing stri it will be understood that a similar sealing strip will be employed on the opp ite upstanding flange of the suction gland. Also should the low pressure in the cylinder holes which are passing over the "off-going seal tend to increase the pressure of that seal against the cylinder, this tendency can be taken into account and offset by supplying air to the expansion tubes [8 under two different pressures, which may be regulated independently of each other, so that in actual operation the total pressure of the oif-going seal against the cylinder, resulting from vacuum in the cylinder holes and the tube pressure itself may be equalized to the pressure exerted by the expansion tube itself on the oncoming seal.

In practice a small amount of clearance will be provided between the sides of the sealing strip and the vertical slot in which it moves so that there will be real freedom of movement of this seal.

The sealing strip mounting blocks, fastened to the suction glands as illustrated in the drawing, are readily removable for replacement of any of the parts thereof or whenever it may be desired to mount a sealing st ip of a different dimension or at a slightly different location.

While the drawing shows a preferred embodiment of the invention, it should be understood that the invention is susceptible of some variation without departing from the spirit and scope of the invention as defined in the appended claims.

Having shown and described my invention, I claim:

1. In combination with a suction roll including a perforated cylinder and a stationary suction gland mounted in the cylinder, a sealing strip mounting block positioned on the suction gland and having an elongated slot open toward the adjoining cylinder wall, an elongated sealing strip slidably mounted in said slot, an expansible tube positioned in the bottom of said slot for pressing the sealing strip outwardly of the slot toward the adjoining cylinder wall, means forsupplying a gaseous fluid under pressure to said tube, said mounting block having passage means on opposite sides of said slot for introducing water into said slot alongside said sealing strip above said tube, means connected with said passage means for supplying water thereto under pressure, and longitudinal packing strips positioned near the open end of said slot and extending along the length of said slot for engaging the sides of the sealing strip to prevent the entry of foreign matter between said sealing strip and said slot.

2. In combination with a suction roll including a. perforated cylinder and a stationary suction gland mounted therein, a sealing strip mounting block secured to a longitudinal edge portion of the suction gland, said block having a longitudinally extending slot opening toward the adjacent cylinder wall, a sealing strip slidably mounted in said slot for engagement with the perforated cylinder wall, an expansible tube at the inner end of said slot for urging said strip against the cylinder wall, packing strips positioned near the upper margin of said slot engaging the sides of said strip, means for supplying a gaseous fluid under pressure to said expansible tube, said block having a plurality of passages positioned for delivering water to the opposite longitudinal sides of said strip, a passage in the suction gland wall communicating with said passages in the mounting block, and means connected to said gland wall passage for delivering 'water under pressure to said block passages.

3. A sealing strip assembly for a suction roll having a rotatably disposed suction drum comprising a demountable mounting block for attachment to a suction gland of a suction roll. said block having a longitudinally extending slot, a sealing strip slidably mounted in said slot, an expansible tube in the bottom of said slot for urging the sealing strip outwardly from the slot to resilient contact with said drum, said block having passage means for supplying water to the opposite sides of said strip within said slot for lubricating the movement of the strip in the slot, and sealing means resiliently interposed between and in extended surface engagement with said block and said strip adjacent the outer end of said slot for preventing the leakage of water therefrom.

4. A seal assembly for a suction gland-equipped suction roll which comprises a mounting block adapted for detachable mounting on the suction gland and having a slot extending lengthwise thereof, a sealing strip slidably mounted in said slot and protruding therefrom for contact with the suction roll, and elongated longitudinal packing strips positioned near the open end of the slot and coextensive with said slot for engaging the sides of said strip to prevent the entry of foreign matter between the strip and the adjacent walls of said slot.

5. A suction roll seal assembly for attachment to a suction gland positioned within a rotatably disposed suction drum comprising a sealing strip holder, means for removably securing said holder to said suction gland, a pair of outwardly extending generally parallel arms on said holder extending axially of said drums and terminating in closely spaced relation to the inner periphery of said drum to define an elongated slot therebetween and a transverse liquid passage communicating with said slot intermediate the length thereof, an inflatable bladder bottomed in said slot and adapted to be connected to a source of air under pressure, an elongated sealing stri guided in said slot for movement therein, said strip being bottomed against said bladder and resiliently urged thereby into contact with the inner periphery of said drum, means for introducing a liquid lubricant for said stri into said transverse passageway to lubricate contacting faces of said strip and said arms, and an elongated packing strip coextensive with said strip and confined between said arms and said strip to prevent entry of foreign matter therebetween.

LLOYD HORNBOSTEL.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 470,086 Taylor Mar. 1, 1892 562,390 Gould June 23, 1896 1,800,149 Miller et al Apr. 7, 1931 2,290,777 Street July 21, 1942 2,312,519 Berry Mar. 2, 1943 2,395,533 Clem Feb. 26, 1946 FOREIGN PATENTS Number Country Date 26,049 Great Britain of 1909 27,180 Great Britain of 1909 421,020 France Feb. 13, 1911 656,453 Germany Feb. 7. 1938 

